NAME
MIME::EncWords - deal with RFC 2047 encoded words (improved)
SYNOPSIS
*MIME::EncWords is aimed to be another implimentation of MIME::Words so
that it will achive more exact conformance with RFC 2047 (former RFC
1522) specifications. Additionally, it contains some improvements.
Following synopsis and descriptions are inherited from its inspirer,
then added descriptions on improvements (**) or changes and
clarifications (*).*
Before reading further, you should see MIME::Tools to make sure that you
understand where this module fits into the grand scheme of things. Go
on, do it now. I'll wait.
Ready? Ok...
use MIME::EncWords qw(:all);
### Decode the string into another string, forgetting the charsets:
$decoded = decode_mimewords(
'To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= ',
);
### Split string into array of decoded [DATA,CHARSET] pairs:
@decoded = decode_mimewords(
'To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= ',
);
### Encode a single unsafe word:
$encoded = encode_mimeword("\xABFran\xE7ois\xBB");
### Encode a string, trying to find the unsafe words inside it:
$encoded = encode_mimewords("Me and \xABFran\xE7ois\xBB in town");
DESCRIPTION
Fellow Americans, you probably won't know what the hell this module is
for. Europeans, Russians, et al, you probably do. ":-)".
For example, here's a valid MIME header you might get:
From: =?US-ASCII?Q?Keith_Moore?=
To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?=
CC: =?ISO-8859-1?Q?Andr=E9_?= Pirard
Subject: =?ISO-8859-1?B?SWYgeW91IGNhbiByZWFkIHRoaXMgeW8=?=
=?ISO-8859-2?B?dSB1bmRlcnN0YW5kIHRoZSBleGFtcGxlLg==?=
=?US-ASCII?Q?.._cool!?=
The fields basically decode to (sorry, I can only approximate the Latin
characters with 7 bit sequences /o and 'e):
From: Keith Moore
To: Keld J/orn Simonsen
CC: Andr'e Pirard
Subject: If you can read this you understand the example... cool!
Supplement: Fellow Americans, Europeans, you probably won't know what
the hell this module is for. East Asians, et al, you probably do.
"(^_^)".
For example, here's a valid MIME header you might get:
Subject: =?EUC-KR?B?sNTAuLinKGxhemluZXNzKSwgwvzB9ri7seIoaW1w?=
=?EUC-KR?B?YXRpZW5jZSksILGzuLgoaHVicmlzKQ==?=
The fields basically decode to (sorry, I cannot approximate the
non-Latin multibyte characters with any 7 bit sequences):
Subject: ???(laziness), ????(impatience), ??(hubris)
PUBLIC INTERFACE
decode_mimewords ENCODED, [OPTS...]
*Function.* Go through the string looking for RFC-1522-style "Q"
(quoted-printable, sort of) or "B" (base64) encoding, and decode
them.
In an array context, splits the ENCODED string into a list of
decoded "[DATA, CHARSET]" pairs, and returns that list. Unencoded
data are returned in a 1-element array "[DATA]", giving an effective
CHARSET of "undef".
$enc = '=?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= ';
foreach (decode_mimewords($enc)) {
print "", ($_[1] || 'US-ASCII'), ": ", $_[0], "\n";
}
** However, adjacent encoded-words with same charset will be
concatenated to handle multibyte sequences safely.
* Whitespaces surrounding unencoded data will not be stripped so
that compatibility with MIME::Words will be ensured.
In a scalar context, joins the "data" elements of the above list
together, and returns that. *Warning: this is information-lossy,*
and probably *not* what you want, but if you know that all charsets
in the ENCODED string are identical, it might be useful to you.
(Before you use this, please see "unmime" in MIME::WordDecoder,
which is probably what you want.) ** See also "Charset" option
below.
In the event of a syntax error, $@ will be set to a description of
the error, but parsing will continue as best as possible (so as to
get *something* back when decoding headers). $@ will be false if no
error was detected.
* Malformed base64 encoded-words will be kept encoded. In this case
$@ will be set.
Any arguments past the ENCODED string are taken to define a hash of
options. ** When Unicode/multibyte support is disabled (see
"USE_ENCODE" in MIME::Charset), these options will not have any
effects.
Charset **
Name of character set by which data elements in scalar context
will be converted. The default is no conversion. If this option
is specified as special value "_UNICODE_", returned value will
be Unicode string.
Note: This feature is still information-lossy, *except* when
"_UNICODE_" is specified.
Detect7bit **
Try to detect 7-bit charset on unencoded portions. Default is
"YES".
Mapping **
In scalar context, specify mappings actually used for charset
names. "EXTENDED" uses extended mappings. "STANDARD" uses
standardized strict mappings. Default is "EXTENDED".
encode_mimeword RAW, [ENCODING], [CHARSET]
*Function.* Encode a single RAW "word" that has unsafe characters.
The "word" will be encoded in its entirety.
### Encode "<>":
$encoded = encode_mimeword("\xABFran\xE7ois\xBB");
You may specify the ENCODING ("Q" or "B"), which defaults to "Q". **
You may also specify it as ``special'' value: "S" to choose shorter
one of either "Q" or "B".
You may specify the CHARSET, which defaults to "iso-8859-1".
* Spaces will be escaped with ``_'' by "Q" encoding.
encode_mimewords RAW, [OPTS]
*Function.* Given a RAW string, try to find and encode all "unsafe"
sequences of characters:
### Encode a string with some unsafe "words":
$encoded = encode_mimewords("Me and \xABFran\xE7ois\xBB");
Returns the encoded string.
** RAW may be a Unicode string when Unicode/multibyte support is
enabled (see "USE_ENCODE" in MIME::Charset). Furthermore, RAW may be
a reference to that returned by "decode_mimewords" on array context.
In latter case "Charset" option (see below) will be overridden (see
also a note below).
Note: * When RAW is an arrayref, adjacent encoded-words (i.e.
elements having non-ASCII charset element) are concatenated. Then
they are splitted taking care of character boundaries of multibyte
sequences when Unicode/multibyte support is enabled. Portions for
unencoded data should include surrounding whitespace(s), or they
will be merged into adjoining encoded-word(s).
Any arguments past the RAW string are taken to define a hash of
options:
Charset
Encode all unsafe stuff with this charset. Default is
'ISO-8859-1', a.k.a. "Latin-1".
Detect7bit **
When "Encoding" option (see below) is specified as "a" and
"Charset" option is unknown, try to detect 7-bit charset on
given RAW string. Default is "YES". When Unicode/multibyte
support is disabled, this option will not have any effects (see
"USE_ENCODE" in MIME::Charset).
Encoding
The encoding to use, "q" or "b". ** You may also specify
``special'' values: "a" will automatically choose recommended
encoding to use (with charset conversion if alternative charset
is recommended: see MIME::Charset); "s" will choose shorter one
of either "q" or "b". Note: * As of release 1.005, The default
was changed from "q" (the default on MIME::Words) to "a".
Field
Name of the mail field this string will be used in. ** Length of
mail field name will be considered in the first line of encoded
header.
Folding **
A Sequence to fold encoded lines. The default is "\n". If empty
string "" is specified, encoded-words exceeding line length (see
"MaxLineLen" below) will be splitted by SPACE.
Note: * Though RFC 2822 states that the lines are delimited by
CRLF ("\r\n"), this module chose LF ("\n") as a default to keep
backward compatibility. When you use the default, you might need
converting newlines before encoded headers are thrown into
session.
Mapping **
Specify mappings actually used for charset names. "EXTENDED"
uses extended mappings. "STANDARD" uses standardized strict
mappings. The default is "EXTENDED". When Unicode/multibyte
support is disabled, this option will not have any effects (see
"USE_ENCODE" in MIME::Charset).
MaxLineLen **
Maximum line length excluding newline. The default is 76.
Minimal **
Takes care of natural word separators (i.e. whitespaces) in the
text to be encoded. If "NO" is specified, this module will
encode whole text (if encoding needed) not regarding
whitespaces; encoded-words exceeding line length will be
splitted based only on their lengths. Default is "YES".
Note: As of release 0.040, default has been changed to "YES" to
ensure compatibility with MIME::Words. On earlier releases, this
option was fixed to be "NO".
Replacement **
See "Error Handling" in MIME::Charset.
Configuration Files
**
Built-in defaults of option parameters for "decode_mimewords" (except
'Charset' option) and "encode_mimewords" can be overridden by
configuration files: MIME/Charset/Defaults.pm and
MIME/EncWords/Defaults.pm. For more details read
MIME/EncWords/Defaults.pm.sample.
VERSION
Consult $VERSION variable.
Development versions of this module may be found at
.
SEE ALSO
MIME::Charset, MIME::Tools
AUTHORS
The original version of function decode_mimewords() is derived from
MIME::Words module that was written by: Eryq (eryq@zeegee.com), ZeeGee
Software Inc (http://www.zeegee.com). David F. Skoll
(dfs@roaringpenguin.com) http://www.roaringpenguin.com
Other stuff are rewritten or added by: Hatuka*nezumi - IKEDA Soji
.
All rights reserved. This program is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.